WASHINGTON (CNN) – A new national poll indicates that Americans think Hillary Clinton's performance as secretary of state deserves a grade of B-.

The CNN/Opinion Research Corporation survey, released Thursday as the Obama administration approaches 200 days in office, asked respondents to use a grading scale of A, B, C, D, and F, where A is excellent and F is very poor.

Twenty-two percent of those questioned gave Clinton an A, 35 percent a B, 22 percent a C, 11 percent a D and 8 percent an F. The secretary of state's grade averaged out to a B-.

Clinton also received a grade of B- in a CNN poll taken earlier this year as the Obama administration approached 100 days in office.

The CNN/Opinion Research Corporation poll was conducted July 31-August 3, with 1,136 adult Americans questioned by telephone. The survey's sampling error is plus or minus 3 percentage points.